A double negative is a no-no. – Author unknown

Do not be surprised when those who ignore the rules of grammar also ignore the law. After all, the law is just so much grammar. – Robert Brault, rbrault.blogspot.com

A semicomma, we should note, doesn’t exist; we just made the word up. But it sounds like a punctuation mark that should exist, doesn’t it? – Richard Lederer and John Shore, Comma Sense: A Fun-damental Guide to Punctuation

There are people who embrace the Oxford comma and people who don’t, and I’ll just say this: never get between these people when drink has been taken. – Lynne Truss, Eats, Shoots & Leaves: The Zero Tolerance Approach to Punctuation